|“||As long as it's living, then Cioccolata's Green Day... will kill it... always...||”|
Green Day is a humanoid Stand with black lines over its body and cylinders on its head, which are constantly releasing a fog like smoke. It's said that because its user, Cioccolata, is full of malice, Green Day developed an ability to inflict tremendous pain and damage to its victims' bodies. The Stand's own personality, if existent, is unknown.
Mold Infestation: Green Day's main ability is to produce a potent mold that can destroy the flesh of its victims in an instant. The mold is only produced when the potential victims drop below a certain altitude, this altitude being determined by one's own height. If one lowers themselves, such as to pick up something or if they're on the floor, they will fall victim to the mold. The lower the altitude the faster it spreads; a person lying on the floor can be consumed in a matter of seconds, while someone bending over may take a bit longer to die.
However, things that are not living, such as Bruno Bucciarati's body after he was beaten by King Crimson, are not affected; it also can only infest the users but not the Stands, since Sex Pistols are not covered in mold even when they drop. Secco uses this property to protect himself from the mold, by wrapping himself in the coat of Oasis. It is unknown if other coat-Stands such as White Album can survive in this way as well.
Dismemberment Control: A hidden ability of Green Day is that Cioccolata can implant its mold within his severed limbs and body parts. Doing so allows Cioccolata to control his limbs freely, as if they were still attached to his body. This allows him to ambush opponents and/or attack them from multiple directions and grants Cioccolata access to smaller places that he wouldn't normally be able to access.